1-aryloxindoles and their preparation



United States Patent N0 Drawing. Filed Feb. 3, 1961, Ser. No. 86,876 25 Claims. (Cl. 260-319) This invention relates to a novel process for producing indole derivatives, to novel compounds produced thereby, and to intermediates therefor.

In particular the invention is concerned with a process for preparing l-aryl'3-aroyloxindo1es from N-aroyl-2 carbo-lower-alkoxymethyldiphenylamines, with certain novel l-aryloxindoles, and with intermediates in the preparation of said oxindoles.

It has been discovered that if an N-aroyl-2-carbo-loweralkoxymethyldiphenylamine is heated with a strong base under anhydrous conditions, a cyclization reaction takes place and there is produced a 1-aryl-3-aroyloxindole.

The reaction is illustrated in simplest terms by the following transformation showing the conversion of N-benzoyl-Z-carbomethoxymethyldiphenylamine to 1-phenyl-3- benzoyloxindole CHZCOOCH3 CH-C 0 05115 The scope of the process of the invention is, however, not limited to the specific illustration given above. Any

one or more of the three phenyl rings can be further substituted by one or more substituents inert under the con-. ditions of the reaction. Exemplary of such inert substituents are lower-alkyl of one to four carbon atoms, loweralkoxy of one to four carbon atoms, lower-alkylmercapto -of one to four carbon atoms, halogen (including fluorine, chlorine, bromine and iodine), carboxy, carbo-loweralkoxy (the alkyl group having from one to four carbon atoms), nitro, and trifluoromethyl.

The catalyst for the cyclization reaction can be any strong base useful in efiecting Claisen-type elimination reactions. Such strong bases include alkali metal loweralkoxides, amides and hydrides. The reaction takes place in an inert organic solvent, such as benzene, toluene, Xy lene, dioxane, petroleum ether and the like, preferably at a temperature between about 50 C. and 150 C.

Preferred aspects of the invention are set forth in the "Ice C H20 0 O-lovrer-alky NaOMe 0 b R on- Ar -HOAC I i A1" (v) (VI) In the above formulas, Ar and Ar are monocarbocyclic aryl radicals, and thus stand for phenyl or phenyl substi. tuted by inert substituents as described hereinabove. R is hydrogen or lower-alkoxy having from one to four carbon atoms. Lower-alkyl encompasses alkyl groups having from one to four carbon atoms.

A 2-carbo-lower-alkoXymethyl-N-aroylaniline of Formula I is converted to the corresponding imino chloride of Formula II by reaction with phosphorus pentachloride. The imino chloride (II) is then condensed with phenol or a substituted phenol in the presence of a strong alkali metal base such as sodium methoxide. The phenol thus reacts in the form of its alkali metal salt. The product produced is an N-[2-(carbo-lower-alkoxymethyl)phenyl]- benzimino aryl ether (HI) The latter upon heating, preferably at a temperature between about C. and 300 C., is rearranged to an N-aroyl-Z-carbo-lower-alkoxymethyl-diarylamine of the Formula IV. The next step is the cyclization reaction described hereinabove, resulting in a l-aryLB-aroyloxindole of Formula V. The 3-aroyl group can be hydrolyzed with hydrobromic acid in aqueous acetic acid to give a 1-aryloxindole of Formula VI.

The structure of the compounds of Formula V was further indicated by the fact that the compound produced by cyclization of N-benzoyl-Z-carbomethoxymethyldiphenylarnine was identical with authentic 1-phenyl-3-benzoyloxindole produced by reacting l-phenyloxindole with ethyl benzoate in the presence of sodium ethoxide.

In the cyclization reaction lV- V small amounts of high melting by-products were formed. It was determined that they had the following structure:

R C0 0 0 Z -Ar Al" (VII) wherein R, Ar and Ar have the meanings given above, and Z is hydrogen or lower-alkyl. The compounds where Z is hydrogen are produced by hydrolysis of the corresponding lower-alkyl esters. The structure VII was proved by independent synthesis. Ethyl benzoylacetate was condensed with N,N-diphenylhydrazine and the product, -(C H )gNN=O(C H )CH COOC H was converted to VII (Ar, Ar'=C H R=H, Z=C H by the Fischer indole synthesis. Saponification gave the acid (Z=H) which was treated with thionyl chloride and then methanol to give the methyl ester (kOH The last proved to be identical with the by-product obtained by cyclization of 1V (Ar, Ar'=C H R=H, lower-alkyl=OH The compounds of Formula V are beta-dicarbonyl compounds and thus possess an active hydrogen at the 3-position of the indole ring. Consequently, they are acidic, .soluble in aqueous alkali, and form metal salts with strong inorganic bases. These salts are the equivalents of the free acids specifically claimed. Preferred types of salts are those which are non-toxic and water-soluble, such as the sodium or potassium salts; aithough'other'salts, for

example, the lead, calcium andmorpholine salts are 1186-. ful in'purification and characterization of the free acids.

Similarly, the compounds 'of'Formula VII where Z is hydrogen are acids and form salts with strong inorganic or organic bases. Again, said 'salts' are the equivalents of the free acids specifically claimed. 7

Pharmacological evaluation of compounds of Formulas V. and VI has shown that they possess pharmacodyn-amic activity, for example, hypotensive activity.

Chemotherapeutic evaluation has demonstrated that compounds of Formula YII possess antibacterial activity.

The following examples. will further illustrate the inventi-on without the latter being limited thereto.

A; 'IMINQ ZOHLORIVDES 11 Example A]. v

(a) Mei'hyl Z-benzamidohhenylacetete [-I; R is I-L Ar' .is C l-I lower-alkyl is CH I 'Methyl' o-nitrophenylacetate, prepared in 95% yield.

from the free acidand methanolic hydrogen chloride, was hydrogenated in'methanol with aplatinum catalyst. The

solventwasthen removed at room temperature to'givea' residue of crude methyl o-amin-ophenylacetate as an orange oil. The latter was then caused .to react with benzoyl chloride in pyridine to yield methyl '2-benzamidophenylacetate.

(b). Imino. chzoriaet na is H, Ar is c 11 lower-alkyl 3]'- 1 p w .Methyl '2-be'nzamidophenylacetate (5 6.5 g., 0.21 mole) and 43.7 g. (0.21 mole) of phosphorus pentachloride were ExampleAfi (a) Methyl 2 b rjom 3,5 liichlorohen zdini do) alkyl is CH can be prepared by replacing the benzoyl chloride in Example A1,.part (a) by 2-brom'o-3,5-dichlorobenzoyl chloride, V 7 V (b) The imino chloride [11; R isrH, Air is 7 V V 2.4BI-'3,5-C12C(-;H2 '7 V V lower-alkyl is CH5] can be. prepared by reacting methyl 2-(2-bromo 5 3,5 dichloro be'nzamido)phenylacetate with phosphorus pentachloride according to thev manipulative above in Example Al, part (b);

procedure described 7 Example A6 (a)' Methyl 2 (4 butoxybenzqmido)phenylheetate [I;: R is H, Ar is 4 (C H )C H lower-alkyl is CH lcan be prepared by replacing the benzoyl chloride in Example Al,

' part (a) by'4-butoxybenzoyl chloride.

-(b) The imino clz lo rideifll; n is Aris (C4 9) s 4 can be prepared by lower-alkyl. is CH 7 reacting methyl 2-(4-butoxybenza-mido) phenylacetate ewith phosphorus" pentachloride according to the manipulative procedure de-;

"scribed above in Example Al part.(b).

mixed, and a spontaneous reaction occurred. .The reac tion was-completed by heating the mixture on a steam bath ;until the evolution 'o'f hydrogen chloride ceased. The phosphorus oxychl-oride which had formed was then removedin vacuo at -'C., and the last traces Were'removed by codistillation with toluene. was obtained as a red oil.

Example A2 The imino chloride (a).Ethyl Z-benzalnidophenylacelale I; R is H, 'Al" is C H lower-alkyl is C H was prepared by hydrogenating ethyl o-nitrophenylacetate.with platinum in'absolute ethanolgand reaotin'g .the resulting product with benzoyl chloride in pyridine. V (b)' The imino chloride [11; Ris H, Ar is C H lower* alkyl is C H was preparedfrom 51 g. of-et-hyl Z-benzamidophenylacetate and phosphorus pent-achloride accord.

ing .to the manipulative procedure described above in EX- Vample A-1,- partEQb). 7

Example A3 (a) Methyl Z-bnrzamido4-methbryphenyllzcerate [I; R is (EH 0, Ar is C H .lower-alkyl is CH can be prepared from theknown 2-arnino-5-methoxyphenylace-tic acid by esterification with methanolic hydrogen chloride and 'acylation with benzoyl chloride in' pyridine. '(b) The imino chloride [11; R is CHgO, Ar is C H lowerealkyl 'is CH can be preparedifrorn. methyl 2-.

benzamido4+methoxyphenylacetate and phosphorus pentachloride according to. the manipulative procedure 7 escribed above .in Example Al pant. (b);

. 1 Example A4 -(a) Methyl 2- (3 bromobenzamido)phenylacetale {Ii R is H, Ar is 3'-BrC H lower-alkyl is. CH can be pre- .pared by replacing the benzoyl chloride in Example A1; part (a) by 3-bromobenzoyl chloride.

-;(b)-The' imino chloride [11; R is H, Ar is 3-'BrC H 'lower a-lkyl jis CH can b e prepared by reacting methyl 2- (3-bromoben2amido)phenylacetate with phosphorus pentachloride according to the manipulative procedure described above in Example A1, part (b),

(a) Methyl 2-(4-chlorqberrzdmido)phenylaceiate' 1; R is "H, Ar is 4-ClC I-I lower-alkyl is CH3] can be prepared by replacing'the benzoyl chloride in Example 7 A1, part (a) by 4-chlorobenzoyl chloride;

(is) The imino chloride [11; Ris H, Ar is described above in Example A1, part (b). p 7 4 Exz'lmple A8 7 i (a) Methyl 2-($;chZora-3,4-dinitr0benzamidol pkenyla acetate [1; R is H, Ar is5 -Cl-3,4-(NO C H lower-alkyl is CH can be prepared by replacing the benzoyl chloride in Example Al part (a) by 5+chloro-3,4-dinitrobenzoyl V chloride.

manipulative procedure described above (b) The imino chloride njR Vis'r 'Ar is ici a (NO MC H lower-alkyl is CH can be prepared by re-.

' acting methyl 2-(5-chloro-3,4-dinitrobenzamido)phenyl acetate with phosphorus pentachloride according to the part (b).'- v Example A9 '(a) M t l 2 (2,3-diethoxybenzamz'do)phehylacetdie' [1; R is H, Ar is 2,3-( C H5O) C H lower-alkyl isCH V7 can be preparedby replacing theb'enzoyl chloride in Ex ample A1, part (a) byi2,3-diethoxybenzoyl chloride. p

(b) The imz'no chloride [II; R is H, 'Ar-"is 2 ,3

(C H O) C H rlower-allgyl is CH can be prepared by reacting methyl 2-(2,3-diethoxybenzamido)phenylacetate with phosphorus pentachloride according'to the 'manipula- 7 two procedure describedabove in Example Al, part (b).

. Example 0 (a) Methyl 2 -(3-flhorgbenzamidojphenylizceiateII; R i is H, Ar is 3-FC H lower-alkyl is CH can be prepared Y by replacing the benzoylchloride in Example Al, part 5 (a) by 3-fluorobenzoyl chloride.

7 r (b) The imz'no chloride 11; His H,"A r is s-rc rn, lower-alkyl is CH can be prepared by reacting methyl 2-(3-fluorobenzamido)phenylacetate with phosphoruspe'n-Q tachloride according to the manipulative procedure described abovein Example A 1 part (b).

Example 411.: V I (a) Methyl '2-(4-i0d0benzamid0)phenylacetate {1; R" is H, Ar is 4-IC H lower-alkyl is CH can be prepared .7 e e, lower-alkyl is CH can be prepared by reacting methyl 2- (4- chlorobenzamido)phenylacetate with phosphorus pentachloride according to the manipulative procedure in Example A 1;

by replacing the benzoyl chloride in Example A1, part (a) by 4-iodobenzoyl chloride.

(b) The imino chloride [11; R is H, Ar is 4-IC H lower-alkyl is CH can be prepared by reacting methyl 2-(4-iodohenzamido)phenylacetate with phosphorus pentachloride according to the manipulative procedure described above in Example A1, part (b).

Example A12 (a) Methyl 2 (3-methyllhi0benzamid0)phenylacetate [1; R is H, Ar is 3-CI-I SC H lower-alkyl is CH can be prepared by replacing the benzoyl chloride in Example A1, part (a) by S-methylthiobenzoyl chloride.

(b) The imz'no chloride [11; R is H, AI is 3-CH SC H lower-alkyl is CH can be prepared by reacting methyl 2-( 3-methylthiobenzamido phenylacetate with phosphorus pentachloride according to the manipulative procedure described above in Example A1, part (b).

Example 13 (a) Methyl 2-(2,4,6-trimethylbenzamido)phenylacetate [1; R is H, AI is 2,4,6-(CH C H lower-alkyl is CH can be prepared by replacing the benzoyl chloride in Example A1, part (a) by 2,4,6-trimethylbenzoyl chloride.

(1)) The imino chloride [11; R is H, Ar is 2,4,6- (CH C H lower-alkyl is CH can be prepared by reacting methyl 2-(2,4,6-trimethylbenzamido)phenylacetate with phosphorus pentachloride according to the manipulative procedure described above in Example A1, part (b).

Example A14 (a) Methyl 2- (trifloaromethylhenzamido)phenylacetare [1; R is H, Ar is 4-F CC 1-1 lower-alkyl is CH can be prepared by replacing the benzoyl chloride in Example A1, part (a) by 4-fluoromethylbenzoyl chloride.

(b) The imino chloride [11; R is H, Ar is 4-F CC H lower-alkyl is CH can be prepared 'by reacting methyl 2-(trifluoromethylbenzamido)phenylacetate with phosphorus pentachloride according to the manipulative procedure described above in Example A1, part (b).

Example A15 B. N [2- CARB O-LOWER-ALKOXYME'I'HYL) PHENYL]BENZIM1NO ARYL ETHERS (111) Example B] N [2 (carbomethoxymethyl)phenyl] benzimino 2- carbomethoxyphenyl ether [111; R is 1-1, Ar isC 1-1 Ar is 2-(CH OOC)C H lower-alkyl is CH A solution of 12.4 g. (0.23 mole) of sodium methoxide in 200 ml. of methanol was flushed with nitrogen and cooled in an ice bath. Methyl salicylate (35.0 g., 0.23 mole) in 50 m1. of methanol was then added quickly with stirring. A solution of the imino chloride from Example A1, part (a) in 65 ml. of absolute ether was then added during five minutes, and the mixture was stirred for three hours at room temperature. Water was added and the product was extracted with ether. The red organic solution was dried and the solvent removed to leave an oil which was crystallized from a methanol-hexane mixture to give 59.2 g. of N- [2- (carbomethoxymethyl)phenyl] benzimino 2-carbomethoxyphenyl ether, which when recrystallized twice from methanol gave a sample having the M.P. 62.2-65.2 C. (corn); ultraviolet maxima at 228 and 6 278 111,11. (E=24,000 and 5,400). present at 5.80 and 5.97,u.

Anal.Calcd. for C H NO C, 71.45; H, 5.25; O, 19.83. Found: C, 71.16; H,5.40; O, 19.80.

Example B2 N [2 (Carbethoxymethyhphenyl] benzimino 2 carbomezhoxyphenyl ether [111; R is H, Ar is C H AI is 2-(CH OOC) B H lower-alkyl is C H was prepared from 10.8 g. of sodium methoxide in 205 ml. of meth anol. 34.4 g. of methyl salicylate in 50 ml. of methanol and the imino chloride firom Example A2, part (b) in '50 ml. of anhydrous ether according to the manipulative procedure described above in Example B1. The result ing crude oil was crystallized from absolute ethanol to give 47.2 g. of N-[Z-(carbethoxymethyl)-phenyl]benzimino 2-carbomethoxyphenyl ether which after two recrystallizations from absolute ethanol had the M.P. 92.5- 96 C. (com); ultraviolet maxima at 225 and 278m (E=27,600 and 4,800). Infrared peaks were present in 5.82 and 5.99

AnaL-Calcd. for C H NO C, 71.93; H, 5.55; N, 3.36. Found: C, 71.83; H, 5.52; N, 3.34.

Example B3 N [2 (carbomethoxymethyl) 4 metho-xyphenyflbenzimino Z-carbamethoxyphenyl ether [111; R is OCH Ar is C H Ar is 2-(CH OOC)C H lower-alkyl is CH can be prepared from the im-ino chloride of Example A3, part (b) and methyl salicylate according to the manipulative procedure described above in Example B1.

Infrared bands were Example B4 N- [2-(carbomethoxymethyl)phenyl] benzimino phenyl ether [111; R is H, Ar and Ar are C H lower-alkyl is CH can be prepared from the imino chloride of Example Al, part (b) and phenol according to the manipulative procedure described above in Example B1.

Example B5 N [2 (carbomethoxymethyl)phenyl] 3 bromobenzimz'no 4-chl0r0phenyl ether [111; R is H, Ar is 3-BrC 1-1 Ar is 4-ClC H lower-alkyl is CH can be prepared from the irnino chloride of Example A4, part (b) and 4-chlorophenol according to the manipulative procedure described above in Example B1.

Example B6 N [2 (carhomezhoxymethyl)phenyl] 4 batoxybenzimino 4-br0m0phenyl ether [111; R is H, Ar is 4-(C H )C H Ar is 4-BrC H lower-alkyl is CH can be prepared from the imino chloride of Example A6, part (b) and 4-bromophenol according to the manipulative procedure described above in Example Bl.

Example B8 N [2 (carbomethoxymethyl)phenyl] 4 chlorobenzimino 4-fluor0phenyl ether [111; R is H, Ar is 4-CICSH4, A1" is 4-FC6H4, lower-alkyl is can be prepared from the imino chloride of Example A7, part (b) and 4-fluorophenol according to the manipulative procedure described above in Example B1.

Example B9 N [2 (carbomethoxymethyl)phenyl] 5 chloro- 3,4-dinitr0benzimino 4-i0d0phenyl ether [111; R is H, Ar is 5-Cl-3,'4-(NO C H AI is 4-IC H lower-alkyl ample Bl.

above in Example B1.

V is CH can be prepared from'theuimino chloride rof Example AS, part (b) and 4-iodophenol according to the manipulative procedure described above in Example B1 Example/B10 I N 7 [2 carbmeth01yhiethyl) phenyl] 2,3 diethoxy benzimino 4-methylpheiiyl ether [111; 'R is 1-1,, Ar is 3 CH can be prepared from the imino chloride ofExample' A9, part b) and p-cresolaccording to the manipulative procedure described 'above'in Example B1;

Example B11 7 N [2- (carbomethoxymethyl)phenyll -3 flu orobenzimino 2,4-Idimethylphenyl ether 111; R is H; AI is can be prepared from the im-ino chloride of Example A10, part (b) and 2,4-dimethylphenol according to the manipulative procedure described above in Example Bl.

I Example B12 V V 1N (carbomethoxymethyl)phenyl] 4 iodobenzimino 4-metho1q2phenyl ether [111;R is H, Ar is 4-1C H V 7 Ar is 4-CH OC H lower-alkyl is CH can be prepared from the imino chloride of Example A11, part.(b) and cedure described above in Example Bl. 7 Example 31 I 'N [2 (carbomethoxymet hyl)phenyl] -3 -methylthio- V chloride-of Example A13, part (b) and 3,4,=5-triirrethoxy-v phenol according to the manipulative procedure described above in Example B1.

' i 7 Example B15 V a 7 N [2 (carbomethqxymethyl)phenyl] r 4 trifluoro- 'methylbenzimz'no 3-methoxy4-chl0rophenyl ether [111;

R is H, Aris 4-F CC H Ar i 3-CHgO 4-ClC I-1 loweralkyl is CH can be'prepared from the irnino chloride of Example A14, part (b) and 3-methoxy-4-ch1orophenol' according to the manipulative procedure described'above in Example B 1. w 7 Example B16 N [2 -.(carbomethqxymethyl)phenyl] 2 carbomethoxybenzimino 4-methylthi0phenyl ether [111; R is H, Ar is 2-(CH OOC)C H Ar is 4-CH SC H ,l-OWfiI-filkYl is CH can be prepared from the imino' chloride of Example A15, part (b) is 4-methy-lmercaptophenol according to the manipulative procedure described above in Ex- Example B 17 N [2 (carbomethoxymethyl)phenyl]benzimino 4-nitrophenyl ether 7 [111; R is H, Ar 'is C 11 Ar is 4-O Ncgfi flower-alkyl is CI-1 can be prepared from the imino chloride of Example A1, part (b) and 4-nitrophenol according to the manipulative procedure described 7 Example B1 8 7 N [2-(carbomethoxymethyl)phenyl]benzimino. 4-trifluoromethylphenyl ether [111; R is H, Ar'is C 11 Ar. is 4FCC H ,1loWer-alkyl is CH can be prepared" from the imino chloride of Example A1, part (b) and 4-trition occurred at 5; 79 and 6.06 a 7 a Anal.-Ca1cd.' for C I-1 NO C,71.45; H, 512510, 19.83. Found: C, 71.67; H, 5.34; O, 19.70. j V

V 4-methoxyphe'nol according to the manipulative pro- 7 lower-alkyl is C 11 a 7 Q V N [2 (carbethoxymethyl)phenyl]ben i i g fiuoromethylphenol according tothe manipulative pro ceduredescribed above in Example B1.; a

c. N-AROYL-Z- CARB OLOWER-ALKOXYMETHYL-' DIARYLAMINES Example C1 aiphenylamine [D]; R is H, Ar is C H ,.Ar"is- V 2(CH OOC) C H lowcr-alkyl is CH Q N-[2-(carbomethoxymethyl)phenyl]benzirriino 2 cm bomethoxyphenyl ether 39.2 g.) (Example B1) was heated at 280-295 C. for twelve minutes. The'red gum which resulted was crystallized .irom methanol to give 32.6 g. (83%) of N-benzoyl-Z carbomethoxymethyl-ZQ- carbomethoxydiphenylamine, M.P. 117.012'1.8 (corn) after two recrystallizations from methanol. "The "ultraviolet spectrum exhibited maxima at 250, 280 and Infrared abso'rp- 300 mp (E=l3,070, 6,910 and 5,490).

Example C2 L N benzoyl 2-carbethoxymeihyl 2' carbomethoxydi-.

phenylamine [IV; R is H,'Ar is C H AI is 7 wHa mcsHt methoxyphenyl ether (27.2 g.) (Example B 2)"was heated at 280-295 C. for twelve minutes 'and the product crys- 3.36; 0, 19.16. 'F undi-c,72,07; 5.60; N,. ;1

'tallized from absolute ethanol to give 24.8 g.:( 9l%) of N-ben zoyl-Z carbethoxymethy1-2'=carbomcthoxydiphenyl:

amine, M.P. 114.5-116" C.' (corr.) after two recrystalli zations from ethanol. The ultraviolet spectrum'exhibited maXima at 280 and 294 m;/,-(E= 6,500 and 5,500); .Infrared absorption occurred at 5.75, 5.81 and 6.04

AnaL -Calcd." ror'cs rr No z c, 71.93; 11,555; N.

n Exemple V p N benzoyl-Z-cqrbomethoxymethyl-4-l h etho' bomethpxydiphenylamine [IV; R is OCH Ar is C 11 Ar is 2(CH QOC)Q H lower-alkyl is CH can be prepared by heating -N-[2-(carbomethoxymethyl)phenyl] benzim inoph'enyl ether (Example B3) as described above in Example Cl. 7 7 Example C4 N benz0yl 2-carb0methoicymethyldiphenylainihe [IV;

R is H, Ar and Ar are C H lower-alkyl is CH3] can be prepared :by heating N- [Z-(canbomethoxymethyl)phenyl] benzimino phenyl ether (Example B4) as-described above in Example Cl. r 7 7 It is obtained in the form of colorless prisms, M.P. 132.5134.5 C., when crystallized from absolute ethanol. The ultraviolet spectrum has maxima at 234 and 271 iny. (E: 15,500 and 7,900), and infrared bands are present at 5.78 and 604 A I Example C5 r l I V N (3-brorho ber zzoyl)-2-carb0methbxymethyl-4 chlor rodiphenylamine [IV; R is H, Ar is 3-BrC H uAr' is ft-C1C H lower-alkyl is CH can be prepared by heatmg N [2-(carbomethoxymethyl)phenyl]-3-bromobenzimino 4-chloropheny1 ether (Example B5) as described above in Example C1. .7 V

7 Example C6 1 V N (2 Brom0-3,5-dichl0r0benzoyl)-2-carbomethoxy- C1 1 can be prepared by heating N-[Z-(carbomethoxy- 9 methyl)phenyl] 2-bromo-3,5-dichlorobenzimino 2,4-dichlorophenyl ether (Example B6) as described above in Example C1.

Example C7 N (4-batoxybenzoyl)-2-carbomethoxymethyl-4'-br0- modiphenylamine [IV; R is H, Al is 4-(C H )C H AI is 4-BIC H lower-alkyl is CH can be prepared by heating N [2-(carbomethoxymethyl)phenyl]-4-butoxybenzimino 4-bromopheny1 ether (Example B7) as described above in Example C1.

Example C8 N (4-chl0r0benz0yl)-2-carbomethoxymethyl-4-fla0rodiphenylamine [IV; R is H, Ar is 4-ClC H Ar is 4-FC H loWer-alkyl is CH can be prepared by heat! ing N [2-(carbomethoxymethyl)phenyl]-4-chlorobenzimino 4-fluorophenyl ether (Example B8) as described above in Example C1.

Example C9 N (5 chlaro-3,4-dinitrobenzyl)-2-carb0methoxymelhyl-4'-iod0diphenylamine [IV; R is H, A1 is -C1-3,4- (NO C H Ar is 4-IC H lower-alkyl is CH can be prepared by heating N-[Z-(carbomethoxymethyl)phenyH- 5-chloro-3,4-dinitrobenzimino 4-iod0phenyl ether (Example B9) as described above in Example C1.

Example C10 N (2,3-dieth0xybenz0yl)-2-carb0methoxymef1zyl-4'- methyldiphenylamine [IV; R is H, Ar is z s h s a Ar is 4CH C H loWer-alkyl is CH can be prepared by heating N [2-(carbomethoxymethyl)phenyl]-2,3-diethoxybenzimino 4-methylpheny1 ether (Example B10) as described above in Example C1.

Example C11 N (3-fla0r0benz0yl)-2-carbomethoxymethyl-2',4'-dimethyldiphenylamine [IV; R is H, AI is 3'FC H AI is 2,4-(CH C H lower-alkyl is CH can be prepared by heating N [Z-(carbomethoxymethyl)-phenyl]-3-fluorobenzimino 2,4-dimethylphenyl ether (Example B11) as described above in Example C1.

Example C12 N (4 iodobenzoyl)-2-carb0meth0xymethyl-4-methoxydiphenylamine [IV; R is H, AI is 4IC H AI is 4-CH OC H lower-alkyl is CH can be prepared by heating N-[2-(carbomethoxymethyl)phenyl]-4-iodobenzimino 4-methoxyphenyl ether (Example B12) as described above in Example C1.

Example C13 N (3-methylthi0benz0yl)-2-carb0methoxymethyl-3', 4'-dimethoxydiphenylamine [IV; R is H, AI is Ar is 3,4-(CH O) C H lower-alkyl is CH can be prepared by heating N-[Z-(carbomethoxymethyl)phenyl1-3- methylthiobenzimino 3,4-dimethoxypheny1 ether (Example B13) as described above in Example C1.

Example C14 N (2,4,6-trimethylbenzoyl) 2 carbomethoxymethyl- 5",4',5-trimethoxydiphenylamine [IV; R is H, Ar is 2,4,6- (CH C H Ar is 3,4,5-(CH O) C H lower-alkyl is CH can be prepared by heating N-[Z-(carbomethoxymethyl)phenyl] 2,4,6 trimethylbenzimino 3,4,5 trimethoxyphenyl ether (Example B14) as described above in Example C1.

1e Example C15 N (Z-carbomethoxybenzoyl) 2 carbomethoxymethyl-4'-methylthiodiphenylamine [IV; R is H, Ar is 2- (CH OOC)C H Ar is 4-CH SC H lower-alkyl is CH can-be prepared by heating N-[Z-(carbomethoxymethyl) phenyl]-2-carbomcthoxybenzimiuo 4-methylthiophenyl ether (Example B16) as described above in Example C1.

Example C17 N benzoyl 2 carbomethoxymethyl 4' nitrodiphenylamine [IV; R is H, Ar is C H AI is 4-O NC H lower-alkyl is CH can be prepared by heating N-[2- (carbomethoxymethyl) phenyljbenzimino 4 nitrophenyl ether (Example B17) as described above in Example C1.

Example C18 N benzoyl 2 carbomethoxymethyl 4' trz'fluoromethyldiphenylamine [IV; R is H, Ar is C H Ar is 4-F CC H lower-alkyl is CH can be prepared by heating N-[2-(carbornethoxymethyl)phenyl]benzimino 4-trifluoromethylphenyl ether (Example B18) as described above in Example C1.

D. 1-ARYL-3-AROYLOXINDOLES (V) AND 1,2- DIARYL-3-INDOLECARBOXYLIC ACIDS (VII) Example D1 3 benzoyl 1 (2 carbomethoxyphenyl) oxindole [V; R is H, Ar is C H Ar is 2-(CH OOC)C H and 1-(2- carbomethoxyphenyl) 2 phenyl-3-ind0lecarb0xylic acid [V]1; R is H, Ar is G l-l Ar is 2-(CH OOC)C H Z is H].

Sodium methoxide (2.7 g., 0.050 mole) was added to a stirred mixture of 19.0 g. (0.047 mole) of N-benzoyl-Z- carbomethoxymethyl-Z'-carbornethoxydiphenylamine (Example C1) in of hot benzene'in a nitrogen atmosphere. The solution was then refluxed for one hour with continuous removal of solvent. Dry benzene was added from time to time to prevent the volume of the solution from falling below 50 ml. The red solution was cooled in an ice bath, and water and excess hydrochloric acid were added. The mixture was extracted with ether, and the ether solution was dried and concentrated to leave a solid residue which was recrystallized from methanol. There was thus obtained 12.6 g. (72%) of 3-benzoyl-1- (Z-carbomethoxyphenyl) -oxindole as an orange solid, M.P. 136138 C. (uncorr.).' The analytical sample was obtained after two recrystallizations from methanol, light yellow, M.P. 135.2138.0 C. (corn), The compound gave a dark green color with ferric chloride and had ultraviolet mam'ma at 268 and 320 m (E: 12,600 and 11,300). A chloroform solution showed infrared bands at 5.80, 6.07 and 6.15 1, while the spectrum of the material in potassium bromide had peaks at 5.77, 6.10 and 6.15,:r.

Anal.Calcd. for C H NO C, 74.38; H, 4.61; N, 3.77; O, 17.23. Found: C, 74.56; H, 4.90; N, 3.74; O, 17.10.

3 benzoyl 1 (2 carbomethoxyphenyl) oxindole was found to have a minimum efiective hypotensive dose of about 0.10 rngjkg. of body weight when injected subcutaneously into renal hypertensive rats and measured by the photoelectric foot method of Kersten et al., I Lab. Clin. Med. 32, 1090 (1947).

3-benzoyl-1-(2-carbomethoxyphenyl)oxindole is soluble in aqueous sodium or potassium hydroxide, forming solutions of the sodium or potassium salt, respectively.

' weightcalcd; 371.

. rem calcd; 178.7; Found:'183.0. a 7

' 3-benzoyl-1-(2 carboxyphenyl)oxindole was found to .be 300 mgJkg.

7 While the procedure just described gave reasonably pure material after one recrystallization, a similar experiment in which 'toluene rat her than benzene was used asthe v reaction medium furnished material which melted over a very wide range. 7 When this'material was boiled witha large volume of cyclohexane all ,but a very small fraction of the solid dissolved. 3-benzoyl-l-(2-carboinethoxyphen yl)oxind-ole was obtained from the yellow solution while; the colorless, insoluble material provedtobe1-(2-carbo-.

methoxyphenyl)-2-phenyl-3 -indolecarboxylic acid. The

latterjcompound had the M.P. 253-258 C. (uncorr.) V and gave a' negative. ferric chloride test. .It was further purified by dissolving it in aqueous sodium bicarbonate solution and repr'ecipitating it with acid. 1 One recrystallization from methanol gave the analytical sample, M.P.

254 260 0. (corn). .The ultra violet spectrum had inaxir'na at 235 and 294 mu (E=30,690 and 16,550).

' v The infrared spectrum had bands at 5.80, 5.92 and 6.03 1;

Anal.--Calcd. for c n o c, 74.38; H, 4.61; N,

; Molecular W i of potassium carbonate, 500 of methanol and 120' ml. of water was refluxed for-three'hours, then diluted with Water and washed with ether. The aqueous phase was acidified with hydrochloric acid and the productextracted with ether. The ether solution was dried and concentrated, and the residue was crystallized from a benzenehexane mixture to give, 6.3 'g'. (66%.) of. 3benzoyl-1-(2 carboxyphenyhoxindole, 'M.P. 203 2075 C. (uncorr.). One recrystallization from benzene gave the analytical sample,.light yellow solid, M.P. 208.6- 2l0.0 C. (corn).

The compound gave. a green color with ferric chloride- .The ultravioletspectrum had maxima at 270 and 321 mp (E=1l,400 and 11,03 0). .The infrared spectrum had bands at 5.96, 6.09 an'cl6.12

3.92. Found: 0, 74.01; H, 4.44; N, 3.91.. Neutral .equiva have a minimum effective 'hypotensive dose of: about 1.0 mg/kg. of body weightwhen injectedsubcutaneously into renal hypertensive rates and measured by the photo- 7 stituted indoles instead .of the 1-(2-carbethoxyphnyl) substituted indoles actually obtained, the result canbe, ex-

electric foot method of Kersten et al., loc. cit. The intravenous toxicity (ALD inthe mouse was found to Example D3 methoxypizenyl)-2-phenyl-3 ind0lecarb0xylic acid WE;

The reaction was run under: nitrogen with stirring,

2.76 g. (0.12 mole) of sodium being dissolved in absolute ethanol followed by distillation to dryness- The last traces of ethanol were removed by adding toluene and again distilling to dryness. A solution of 43.0 g. (0.103 mole) of N-benzoyl-2-caIbethoxymethyl-2-carbo methoxydiphenylamine (Example C2) in 125 ml. of dry toluene was then addedall at once. The resulting clear red solution was refluxed for two hours with continuous gage no color with ferric chloride and-had ultraviolet and 321 mp 12514300, nd'ispoo), spectrum of the compoundin: potassium .bromide had bands at 5.8 5, 6106 and 6. 16 L'while a chloroform solu tion gave bands at 5.83,-6.07 and-612,11. :I Aizal.Calcd.-' for C ;H NO C, 74.79; H, 4.97;':N-,'

Mia

Concentration of the mother liquors frc'amthev recrystallizations of 3-benzoyl-l-(2-cai'bethoxypheuyl)oxindolegave 2 g. Of:SOlld, 'M.P; 2 279 C." (uncorrJQTwo. 'rec'rystallizationsfrom absolute ethanol gave l'-(2carbethoxyphenyl)-2-phenyl-3-indolecarboxylic, acid, 278-281 C. (corn), which gavea negative ferric chlo-. ride test. The ultraviolet spectrum had maxima ati237 and 294-m ('E= 3l,100 and 17,340) .The infrared spec- 7 Although the .phcnylamine would be 1-(2-carbomethoxyphenyl)' subplained by transest'erification' brought about'by the use of sodium ethoxide. .This was established by the fact, that when the sodiummethoxide in ExampleD-l was re: placed by sodium ethoxide, an ethyl ester identical with V the product of Example D3 was obtained} Example D4 7 7 i f a 3-benz 0 yl-1-phenylmdindole. [v; R 'is-H, A-r a'nd Ar are C H and melthyl 1,2-diphehyl-3-ind0lcbrlw. ylate [VII; R is H, Arand Ar are ,C, H Z is CH A reaction was carried out between 1.38 g.'of N-ben:

zoyl-Z-carbomethoxymethyldiphenylamine [Schulenberg and Archer, I; Am.'Chem. Soc. 82, 2037 (1960)].and

270 mg. of sodium methoxide according to. the manipulative procedure described above inExample D lQiAfter dilution with water, the reaction mixture was extracted} with chloroform to givea neutral. fraction;- The aqueous solution was acidified and extracted with .chlorofor m,' and the chloroform extracts were dried and concentrated. The residual gum was crystallized'from'isopropylalcohol:

to give 420 mg. (34% ofB-berizyl-l-phenyloxindole as;

gave intense color ,with'ferric chloride, andthe ultraviolet spectrum had 'maxima at. 229,271 and; 323 mg (E='21,600, 11,500 ane a oo Theginfrared spectrum showed hands at ,6.05, 6.10 and 615p-" V a 1 AWL-Calcd. for C H NO N, 4.47.'Found: 'N,

The neutral fraction from theforegoing reaction 'was crystallized from methanol, using activated charcoal for I ethyl One. recrystallization; 7 e551 methanol gave the compound in the form of colordecolorizing purposes, to .give 90mg. (7%) of 1,2-diphenyl-3-indolecarboxylate.

less needles, M.P. 193.5 C. (corr.).' The product maxima at 235 and 2 94 mu (E=29,l00.and 17,100).

4.28. Found: 'C, 80.46; H, 5.16;?N, 4.10. V

7 (b) Alternative preparation of 3-benzoyl-l -ph enyloxin dole.

distillation of solvent and additionof freish, dry toluene.

whenever .needed The work-upwas thesameasthat described for the methyl'ester inExample D1 above. .The product was recrystallizedfrom absolute ethanol't'o give 29.0 g. (73%) of 3' -benzoyl-1 (2-carbethoxyphenyl) oxindole as a yellow solid,'M.P. 134-139? C. (uncorn). Two recrystallization from ethyl acetate gave a light yellow analytical sample, M.P. l42144 C. (corn). .The

. pro'duct gave ,a' dark green color' with ferric chloride and the ultraviolet spectrum exhibited maxima at, 268

' A sodium' ethoxide solution was prepared from 2.3

ggof sodium and 40 ml. of absolute ethanol. 'To this was addedquickly a warm solution from8.4: g. (0.04

mole) of lephenyloxindole, 50 ml..of ethanol and 15 g,

(0.1 mole) of ethyl benzoate. The mixture wa refluxed for two hours, considerable solid precipitating meanwhile. After cooling and diluting with water, the neutral fraction was extracted with ether and unreacted l-phenyloxindole recovered. The. aqueous solution was then acidified I with hydrochloric acid and extracted with ether. The ether extracts were dried and concentrated, and the residue was recrystallized from an ethanol-cyclohexane infrared.

products expected from the cyclization of N-benzoyl 1 2 carbethoxy'methyl 2 carbomethoxydL mixture to give 2.3 g. of 3-benzoyl-l-phenyloxindole as a yellow solid, M.P. 107-114 C. (uncorn). Two recrystallizations from isopropyl alcohol gave a sample having the M.P. 117.5-120.5 C. (corn), which was identical with the 3-benzoyl-l-phenyl0xindole obtained above in part (a), and having no melting point depression upon admixture.

Anal.-Calcd. for C H NO C, 80.49; H, 4.83; N, 4.47. Found: C, 80.82; H, 4.66; N, 4.45.

(c) Alternate preparation of methyl 1,2-diphenyl-3- indolecarboxylate.

(1) Ethyl 1,2-diphenyl-3-ind0lecarl7oxylate [VII; R is H, Al' and A1" are C6H5, Z is C2H5] N,N-diphenylhydrazine and ethyl benzoylacetate were converted to its hydrazone according to Hantzsch et al., Chem. Ber. 30, 3009 (1897), and 39 g. (0.11 mole) of the hydrazone was dissolved in 250 m1. of warm absolute ethanol. To this solution was added 250 ml. of ethanol saturated with hydrogen chloride, and the red mixture was boiled for one hour. The reaction mixture was diluted with water and the product was obtained as an insoluble, yellow solid. One recrystallization from ethanol gave 17.5 g. (47%) of ethyl 1,2-diphenyl-3-indolecarboxylate, M.P. 149-1505 C. (corn). The ultraviolet spectrum had maxima at 235 and 294 m (E=30,000 to 17,600). Infrared absorption occurred at 592 Anal.Calcd. for C H NO C, 80.91; H, 5.61; N, 4.10. Found: C, 81,03; H, 5.64; N, 4.09.

(2) l,Z-diphenyl-3-ind0lecarb0xylic acid [VII; R is H, Ar and Ar are C H Z is H].

A mixture of 3 g. of ethyl 1,2-diphenyl-3-indolecarboxylate, ml. of aqueous sodium hydroxide, 15 ml. of water and m1. of methanol was refluxed for eighteen hours. The mixture was then cooled and the solid product was filtered. This was the sodium salt of 1,2-diphenyl-3indolecarboxylic acid, and it was dissolved in hot water and treated with aqueous hydrochloric acid to give 1,2-diphenyl-3-indolecarboxylic acid, M.P. 247.6 C. (corn) (dec.), after two recrystallizations from acetone. The compound had ultraviolet maxima at 234 and 294 my. (E=29,000 and 16,800). The infrared spectrum had a band at 6.05,u.

. AnaL-Calcd. for (3 11 140,: c, 80.49; H, 4.83; N.

- 1,2-diphenyl-3-indolecarboxylic acid was found to exhibit bacteriostatic activity at dilutions of 1 part in 10,000 when tested against the following organisms: Staph. aureus, E. typhi, Cl. welclzii, Myco. tuberculosis and Ps.

aerugmosa. I

(3) Methyl 1,Z-diphenyl-3-indolecarb0xylate. 1,2-diphenyl-3-indolecarboxylic acid (1 g.) and 10 ml. of thionyl chloride were mixed, the solution being refluxed for forty-five minutes after the initial reaction had stopped.

The excess thionyl chloride was then removed in vacuo, 10 m1. of methanol was added and the mixture refluxed for forty-five minutes. The reaction mixture was cooled and the insoluble product was separated and recrystallized from methanol, using activated charcoal for decolorizing purposes, to give methyl 1,2-dipl1enyl-3-indolecarboxylate in the form of colorless needles, M.P. 195-196 C. (corn). The product was identical with the methyl 1,2-diphenyl-3-indolecarboxylate obtained above in part (a), as shown by mixed melting point and ultraviolet and infrared spectra.

Anal.Calcd. for C H NO C, 80.71; H, 5.23; N, 4.28. Found: C, 80.67; H, 5.10; N, 4.25.

14 Example D5 3 benzoyl I-(Z-carbomethoxyphenyl)-5-methoxyoxindole [V; R is CH O, Ar is C H Ar is and 1-(2-carb0meth0xyphenyl)-2-phenyl-5-methoxy-3-indolecarboxylic acid [VI[; R is CH Ar is C H Ar is 2-(CH OOC)C H Z is H] can be prepared by heating N benzoyl 2-carbomethoxymethyl-4-methoxy-2'-carbomethoxydiphenylamine (Example C3) with sodium methoxide according to the manipulative procedure described above in Example D1. 7

Example D6 3- (3-br0mobenz0yl) -1-(4-chl0rophenyl) oxindole [V; R is H, Ar is 3-BrC H Ar is 4-C1C H and 1-(4-chl0r0- phenyl)-2-(3-br0mophenyl) -3-indolecarb0xylic acid [VII; R is H, Ar is 3-BrC H Ar is 4-ClC H Z is H] can be prepared my heating N-(3-bromobenzoyl)-2-carbomethoxymethyl-4-chlorodiphenylamine (Example C5) with sodium methoxide according to the manipulative procedure described above in Example D1.

Example D7 Example D8 3 (4-butoxybenzoyl) -1-(4-bromophenyl) oxindole [V; R is H, Ar is 4-(C H )C H Ar is 4-BrC H and 1-(4- bromophenyl) 2 (4-butoxypherzyl)-3-indolecarb0xylic acid [VI R is H, Ar is 4- (C H )C H Ar is 4-BrC I-l Z is H] can be prepared by heating N- (4-butoxybenzoyl)- 2-carbomethoxymethyl-4T-bromodiphenylamine (Example C7) with sodium methoxide to the manipulative procedure described above in Example D1.

Example D9 3-(4-chlorobenzoyl)-l-(4-fluor0phenyl) oxindole [V; R is H, Ar is 4-ClC H AI is 4-FC H and 1-(4-flu0r0- phenyl)2-(4-chlorophenyl)-3-indolecarb0xylic acid [VH; R is H, Ar is 4-ClC H Ar is 4-FC H Z is H] can be prepared by heating N (4-chlorobenzoyl)-2-carbomethoxymethyl 4'-fluorodiphenylamine (Example C8) with sodium methoxide according to the manipulative procedure described above in Example D1.

Example D10 3-(5-chl0r0-3,4-dinitr0benz0yl) 1-(4 iodophenyl) 0xindole [V; R is H, Ar is 5-Cl-3,4-(NO C H Ar is 4-IC H and 1-(4-i0d0phenyl) -2-(5-chl0r0-3,4-dinitr0- phenyl) -3-indolecarboxylic acid [VIE R is H, Ar is 5-Cl-3,4-(NO C H AI is 4-IC H Z is H] can be prepared by heating N-(5-chloro-3,4-dinitrobenzoyl)-2- carbomethoxymethyl 4' iododiphenylamine (Example C9) with sodium methoxide according to the manipulative procedure described above in Example D1.

Example D11 3-(2,3-diethoxybenz0yl)-1-(4 methylphenyl)oxindole [V; R is H, AI is 2,3-(C2H50)2C6H3, AI" is 4-CH3C5H4] and 1-(4-methylphenyl)-2-(2,3-diethoxyphenyl)-3 idolecarboxylic acid [VH; R is H, AI is 2,3-(C H O) C H AI is 4-OH C H Z is H] can be prepared by heating N-(2,3 diethoxybenzoyl) 2 carbomethoxymethyl 4- methyldiphenylamine (Example C10) with sodium methoxide'according to the manipulative procedure described above in Example D1.

Example D1.

Example. D12

' 3-(3.-fluorobenz0yl)-1-(2;4 dimethylphenynoxingio le (3-fluorobenzoyl)-2-carbomethoxymethyl-2,4' dimeth- 'yl-diphenylamine (Example C11) with sodium methoxide according tothe manipulative procedure described above in Example D1. 7 s

- Example D13 methoxyphe'nyl)-2-(4-i0dophenyl). 3 indolecarboxylic acid [VI'I; R is H, Ar is 4-IC H Ar is 4-CH OC H Z is HJ'can be prepared by heating N-(4-iodobenz'oyD-2 carbomethoxymethyll' methoxydiphenylamine. (Example C12) with sodium methoxideaccording to the manipw ulative procedure described above in Example D1; 7

Example D14 3-(3-methyltlziobenz0yl) 1 (3,4 dimethoxyphenyl} oxindole [V; R is H, Arfis 3CH SC H Ar is 3,4-

V j methoxymethyl-3,4-dirnethoxydiphenylamine (-Example' C13) with sodium methoxideaccording to the manipulative procedure described above iri' Example D1.

1 Example D15 I V V 3-(2,4,6-irimethylbefizoyl)-1 (3,4,5 -'trimezhoxyphen-' 3 ,4,5- (Cl-I C H and 1-(3,4,5-trime{h0xyphenyl) :2- (2,4,6-trih1ethylpheny -3 ind0lecarb0xylic acid [VIIQR is v benzoyl)2-carbomethoxymethyl 3',4',5' trimethoxydiphenyla'mine (Example 014) with sodium methoxide according to the manipulative procedure described above in Example D1 6 7 3-(4-trifluorometlzylbenzoyl )-1-(3-methoxy 4 chlorophenyloxinddle [V; R is 1-1, AI is 4-F CC H Ari-is Example eating N-benzoyl-2 l carbornethoxymethyl 4' trifluoromethyldiphenylamine (Example C18) with sodium.methoxide according to' the manipulative procedure described above in Example D1., V

i E. I-ARYLOXJNIDOLES (VI) 1 Exilrr zp lie El" I i .(a) 0 (Z-carboxymiilino)phenylacetic acid. V

.of Nabenzoyls 7 carbomethoxymethyl 2' 'carbomethoxydiphenylamine A solution of 16.1 g. (0.04 mole) (Example Cl), of potassium ''hydroxide 150 ml;

of water and 75 ml. of dioxane was refluxed for sixteen- 1 hours. The red solution was washed with etherandthen acidified, with excess hydrochloric acid below 15 C. The} gum' which formed was extracted with ether, and the" etherextractswere dried and concentrated. The residue 7 and recrystallized from ethyl acetate to give o-(2-carboxy 4-triflu0romcthylphenyl) 3 indolecarboxylic acid' [VH;

H] can be prepared by heating .N-(4-trifiuoromethylbenzoyl)-2-carbomethoxymethyl-3'-methoxy 4' -*chloro diphenylarnine (Example C15) with sodium methoxide according to the manipulative procedure described above in Example D1. i

Example. D17

' 3-(2-carbqmetlioxybenzoyl)-]. (4 metiryltlzioplienyl), V

V oxindole [V; R is 'H, Ar is 2- (CH OC)C H Arf is 4- CH SC H and l-(4-methylthiophenyl) -2 (2 carbomethoxyphenyl)-3-indolecarboxylic acid. [VII; R is H, Ar

prepared by V heating .N- (2-carbomethoxybenzoyl) Z car- V bomethoxy-rnethyl-4-methylthiodiphenylamine (Example C16) with sodium methoxide according to the manipula- V tive procedure described above in ExampleDl;

yl-3-ind0lecarboxylic acid [VII; R is H, Ar .is; C H

Ar is 4-O NC H- Z is'H] can be prepared by heating 1 N-benzoyl- 2 -'carbomethoxymethyl 4' f nitrodiphen'yla amine (Example C17) with sodium methoxide according to the manipulativeprocedure described above in Example D1. 7 V V anilino)phenylacetic acid, M.P. 1873-19069 C; (doc) (corn). The ultraviolet spectrum had maxima' 2.20,} 7 '283 and 345 m "(*=:28,700,'9,800 and 7,100),

infrared spectrum had'bands at 3.04 211115.9 5

'Anal.-+Calcd. for c H No c, 66.41;,H, 4.83;N,.2 V 5.16..'Found: C, 66.75; H, 4.76; N,5.09.' Neutral equiv alent Cal cd; 135.6." Found:'136.8.

( b) 1-(0-crirbrixyphenyl)oxindole [V1511 is H, As is hyd-robromic acid wasrefluxed for one-half hour.- The reaction mixture was diluted with water, and the resulting 7 solid was separated and recrystallized from ethyl acetate to give 1;(o carboxyphenyl)oxindole, M.P. 2073- 2103 C. (corr.) .f The ultraviolet spectrum-had a maximum at;

, and infrared peak-swere present at- 248 mp (E=11,400) 5.88 and 6.02

'Anal.-Calcd. :forC 'H NO c, 71.14; H, 4137; Ni I 5.53.. Found: (2, 71.11; H, 4.80; N, 5.39.

-1-'(-o-ca r.boxyp'henyl)oxindole was also obtainedgby re' fiuxing a solution of'6.8 g. (0.018 mole) of 3-benzoyl-l V (2-carbomethoxyphienyl) oxindole '("Example: D1 ml.

of acetic acidand 60 ml. of 48% hydrobromic acid'for one hour. The reactionf mixture was diluted with water, I aiid the resulting product was collected and-recrystallized from an ethyl acetatehexane mixture, using activated charcoal for'decolonizing purposes, to give 1.9 g. of 1-' (o-carboxyphenyhoxindole, M.P. 2075-2095 C. The latter was recrystallized from ethyl acetate to yield asample which was identical, by mixed melting point and in-' 'frared. and ultraviolet spectra, with the l-(2-carboxy- V phenyDoxindole prepared from 2-(2-carboxyN-amii1o) phenyl-acetic acid, described above.

Anal.Found: C, 71.43; H, 4.61; N, 5.43.

1(:o-carboxyphenyl)oxindole was found to have a mini- 7 mum effective hypot'ensive dose of-about"0.1. mg./ -kg.'of

body weight when injected subcutaneously into renal hy- I pertensive rats and measured by the 'method of'Kersten et al., loc. cit.

7 7 Example E2 7 -1-(2-carbethoxyphenyl)oxindole EVI; R isJH, Ar is A solution of 4.9 g. (0.013

was added -arid the mixture was extracted with ether; .The

ether ex-tracts were washed with aqueous,sodium1bica1 bonate, dried, and concentrated to give a gum which .was'

crystallized from hexane. Two' recrystallizations from and the V of o-(2-carboxyanilino) phenyl acetic acid,:10 ml. of acetic acid andil0"ml.fof 48% photoelectric foot 7 mole) of 3-benzoyl-l-(2a 'carbethoxyphenyboxindole (Example: D3), .411 ml. *of

ethanol, 30 ml. of concentrated hydrochloric acid and: 20ml. of dioxane was refluxed for twelve h'ours. "Water 17 isopropyl alcohol gave 1-(2-carbethoxyphenyl)oxindole, M.P. 118.5-121.5 C. (com). The ultraviolet spectrum had maxima at 228, 246 and 280 my. (E: 14,270, 12,030 and 2,210). The infrared spectrum showed one carbonyl band at 5.82,u.

Anal.-Calcd. for C H NO C, 72.58; H, 5.37; N, 4.98. Found: C, 73.04; H, 5.21; N, 4.70.

Example E3 1-(2-carbomethoxyphenyl)-5-methoxyoxindole [VI; R is CH O, AI is 2-(CH OOC)C H l can be prepared by heating 3-.benzoyl-1-(2-carbomethoxypheny1)-5-methoxyoxindole (Example D5) with acetic acid and hydrobromic acid according to the manipulative procedure described above in Example E1.

We claim:

.1. The process for preparing a compound of the formula I Ar which comprises heating with a strong base at a temperature between 50 C. and 150 C. under anhydrous conditions a compound of the formula wherein R is a member of the group consisting of hy drogen and lower-alkoxy, and Ar and Ar each is a member of the group consisting of phenyl and phenyl substituted by from one to three substituents selected from the group consisting of lower-al-kyl, lower-alkoxy, loweralkylmercapto, halogen, carboxy, oarbo-lower-alkoxy, nitro and trifluoromethyl; and the strong base is a compound of the formula M-Z wherein M is an alkali metal and Z is a member of the group consisting of loweraalkoxy, amino and hydrogen.

2. The process for preparing a compound of the formula O orn-ii-ar C O O-lower-alkyl which comprises heating with an alkali metal lower-alkoxide at a temperature between 50 C. and 150 C. under anhydrous conditions a compound of the formula C OO-lower-alkyl (IJH C O O-lower-alkyl Q O=( 3-Ar wherein A1" is phenyl.

3. The process for preparing 3-benzoyl-1-(2-car'oolower-alkoxyphenyhoxindoie which comprises heating N- benzoyl 2 carbo lower alkoxymethy1-2'-carbo-loweralkoxydiphenylamine with an alkali metal lower-alkoxide at a temperature between 50 C. and 150 C. under anhydrous conditions.

4. The process for preparing 3-benzoyl-1-phenyloxindole which comprises heating N-benzoyl-Z-carbo-lower- 'alkoxymethyldiphenylamine with an alkali metal loweralkoxide at a temperature between 50 C. and 150 C. under anhydrous conditions.

18' 5. A compound of the formula CHgC OO-lower-alkyl wherein Ar and Ar each is a member of the group consisting of phenyl and phenyl substituted by from one to three substituents selected from the group consisting of lower-alkyl, lower-alkoxy, loWer-alkylmercapto, halogen, carboxy, carb'o-lower-alkoxy, nitro and trifiuoromethyl, and R is a member of the group consisting of hydrogen and lower-alkoxy.

6. N- [2-(carbomethoxymethyDphenyl]benzimino 2-'carbornethoxyphenyl ether.

7. N-[ 2-(carbethoxymethyDphenyl]benzimino 2 carbomethoxyphenyl ether.

8. .A compound of the formula 0 R- -CH-ii-Ar wherein Ar and Ar each is a member of the group con sisting of phenyl and phenyl substituted by from one to three substituents selected from the group consisting of lower-alkyl, lower-alkoxy, lower-alkylmercapto, halogen, carboxy, carbo-loweralkoxy, nitro and trifluoromethyl, and R is a member of the group consisting of hydrogen and loWer-alkoxy,

14. A compound of the formula wherein Ar is phenyl.

15. 3 benzoyl l-(2-carbomethoxyphenyl)oxindole. 16. 3-benzoyl-l-phenyloxindole. -17. 3-benzoyl-l-(2-carboxyphenyl)oxindole. 18. A compound of the formula R CH3 'wherein R is a membeliiof the group consisting of carboxy and carbo-lower-alkoxmend R is a member of the group consisting of hydrogen and lower-alkoxy.

E19. 1-(2-carboxyphenyl)oxindole,V

20; 1-(2-carbethoxyphenyboxindole.

21. A compound of the formula wherein R is selected from the group consisting ofhydro- 'geri and lower-alkoxy, Ar and 'Ar each is amember of the group consisting of phenyland phenyl substituted by from one to three substituents selected from the group con: sisting of lower-alkyl, lower-alkoxy, lower-alkylmercapto, V halogen, calrboxy, carbo-loWer-alkoxy, nitro and trifiuoromethyl, and Z'is 'a member of the group hydrogen and carbo-loweralkoxy.

2'2. :1-2-diphenylindolee3-carboxylic acid. 23. 1-(2-carb0methoxyphenyD-Z-phenylindole 3 carboxylic acid. 7 r 7 24.fil-(2-ca-nbethoxyphenyl) 2 phenylindole 3 car boXylic acid.

consisting of alkoxy, lower alkylmercapto, halogen, 'carboxy; 'ciarbo-t lower-alkoxy, nitro and trifluoromethyl and Ris a member 7 of the group consisting ofihydrogen and lovmr-alko iy I r "Ref r nc s C ilby h Ex liuer Bergmann, The Chemistry of Acetylene Compounds page 80,'(1948). V

Eldeifield,- Heterocyclici Compounds, yol3,

John Wiley and Sons, Inc., New York, 1952, page 146.

Muller, Methoden der Organischen Chemie, v01; XI/I 4m Edition, pp. 910 -9 13 1957 Wieberg et 21.; I; Am. Chem.

Soc., vol 77, pp. 2205-- 2208 1955 V NICHOLAS S. RIZZO,Brimary Examiner.

IRVING MARCUS, Ex aminer.

Emil B lat UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,189,617 June 15, 1965 Sydney Archer et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4 line 33, for "4-Cl H read 4 ClC H column 6, line 9, for "2- (CH O0C)B H read 2- (CH OOCJ C 11 column 8, lines 48 and 49, for "N- [2- (carbomethoxymethyl)phenyl] benzimino phenyl ether" read N-[Z-(carbomethoxymethyl)4- methoxyphenyflbenzimino 2=carb0methoxyphenyl ether column 11, lines 54 and 55, for "l-(Z-carmethoxyphenyl) in italics,

read l-(2-carbethoxypheny1) in italics; column 13, line 48, for "H, 21" read H, 4.21 column 14, line 7, for "R is CH read R is CH O line 26, for "2Br-3,5- C1 H H read 2-Br3,5-C1 C H column 15, line 58, for

"2- (CH OC) C H read 2- (CH OOC) C H Signed and sealed this 5th day of April 1966.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer 1 Commissioner of Patents 

16. 3-BENZOYL-1-PHENYLOXINDOLE.
 21. A COMPOUND OF THE FORMULA 